Collins New Naturalist Library. David Cabot

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СКАЧАТЬ visited Slieve League in September 1967 when they explored the shattered and gully-seamed cliff above Lough Agh.³³ The most interesting site here is a north-facing outcrop of calcareous schistose rocks extending for about 91 m at an altitude of 400–460 m. They added the brittle bladder-fern and mountain everlasting to the list for the area as well as recording 29 bryophytes of interest. Most of these are characteristic of calcareous rocky outcrops and are generally widely distributed in Ireland, apart from the liverwort Gymnomitrion concinnatum. Two mosses were of particular interest. One was the rare oceanic Leptodontium recurvifolium, providing a link between its previously known Irish localities in Kerry, Galway and Mayo and the western Scottish Highlands. The other, Orthothecium rufescens, also provided a connection between the Scottish Highlands and its previously known Irish sites on the Carboniferous limestones of Sligo and Leitrim, and the Burren, Co. Clare.

       The basaltic plateau of Counties Derry and Antrim

      The upland plateau that forms most of Co. Antrim and three-quarters of eastern Co. Derry is made up of volcanic outpourings that settled out over the landscape in level sheets of lava as recently as 65 million years ago. This is, therefore, the newest part of Ireland. The northern edges of the plateau from Lough Foyle in the north to Belfast Lough in the east are scarped with some impressive cliffs. Where the basalt cooled slowly it split up into a series of vertically jointed polygonal columns which appear in their most dramatic form at the Giant’s Causeway.

      Basalt rocks are composed of 45–55% silica and are classified as basic rocks. They also contain lime, and disintegrate through weathering to produce a comparatively fertile clayey soil, rich in calcium carbonate, providing an attractive environment for many arctic-alpine and alpine plants. Binevenagh, Co. Derry, in the northwestern part of the plateau, looks out over the flat and sandy coastline of Magilligan. Binevenagh has high and dramatic north-facing cliffs, standing over a jumbled, tortured mass of land slips, fallen rock and other debris. These cliffs are famous as one of the best locations in Northern Ireland for a wide range of arctic-alpine and alpine plants growing at uncharacteristically low levels. In fact, the interesting species reported here include two plants not found anywhere else in the province: purple saxifrage, growing sparingly between 275 and 330 m, and moss campion. The moss campion, noted here for its profuse growth and for having flowers that range in colour from deep purple to white (rare), is especially abundant around the screes above Bellarena and at the eastern end of the cliffs. Other species present are alpine scurvygrass (not seen recently³⁴), hoary whitlowgrass, mountain avens on the cliffs at 240–335 m, limestone bedstraw, dwarf willow and juniper.

      Some 58 km further southeast on the high Garron plateau, sitting behind Garron Point on the Antrim coastline, there is an extensive tableland of bare and desolate blanket bog at an elevation of 305–366 m. The bog is deep and wet with many pools and small lakes. Growing here is the rare marsh saxifrage which has bright yellow, often red-spotted, flowers. It was formerly recorded from eight sites in Ireland, spread though six counties. Since 1970 it has only been recorded at this location, at three sites close together on the Nephin Beg Range, Co. Mayo, and at a mineral flush in the wet blanket bog near Bellacorick, Co. Mayo. It is also in decline in Britain.^16,35 On the Garron plateau it grows at a mineral flush, fed by a spring arising from the basalt rocks, and surrounded by the moss Drepanocladus revolvens. Other associated species are daisy, bogbean, selfheal, sharp-flowered rush, bog-sedge, glaucous sedge and large yellow sedge.

      Garron Bog is also the home of two rare alpine sedges that grow at about 300 m in the area southeast from the Falls, in the upper Glenariff River to Trosk, high above the village of Carnlough. The few-flowered sedge occurs fairly commonly over a large area – at about 20 stations – extending over at least two 10 km squares of the national grid. It is a loosely tufted, creeping and mat-forming sedge with a shortish stem, up to 25 cm high and bluntly three-sided. The flowers are on a single bractless spike. First discovered by the Rev. H. W. Lett in 1889, this is one of only two Irish locations, the other being a watery peatland site on the edge of the Red Moss of Kilbroney, a somewhat miniature Garron plateau, at an altitude of 340 m on the Mourne Mountains behind Rostrevor, Co. Down.³⁴ The other sedge is the tall bog-sedge – first found by Miss Elinor D’Arcy in 1901 when she was only 11 years old – well-established on Garron Bog at several sites near pools, where it grows with Sphagnum moss and other sedges. Its leaves are 2–3 mm wide and its stems reach up to 40 cm. Until 1981 the Garron site was thought to be the only place where it grew in Ireland but then another location was discovered in an upland blanket bog in Co. Tyrone where it was growing on the west side of Lough Carn. It was later discovered in 1985 at Mill Lough, near Lough Fea and also at Lough Ouske, Co. Derry.³⁴

      Sperrin Mountains, Co. Tyrone, manifesting erosion of the shallow peats.

       Sperrin Mountains, Counties Tyrone and Derry

      The Sperrin Mountains are made up of old rocks, mainly schists and gneisses in the northern parts, with Old Red Sandstone and a little limestone in the southern sections. The area is covered by upland blanket bog with a series of summits each rising to the region of 610 m. This is where the cloudberry was first found in 1826 by Edmund Murphy and Admiral Jones. It was growing in a single patch on a north-facing slope of wet blanket peatland at an altitude of about 533 m, west of the Dart Mountain summit. Today it flourishes almost submerged in the surrounding vegetation.³⁶ A member of the rose family, it is a small, blackberry-like plant with a white flower – a low, downy, creeping perennial spreading vegetatively by rhizomes. It is described as a ‘shy flowerer and fruiter’ in Ireland as it seldom, if ever, sets fruit. This is thought to be due to the overwhelming presence of plants of a single sex – the stamens (the male organ consisting of a filament and a pollen sac called the anther) usually set in a ring outside the flower centre, and styles (columns of filaments arising from the female organs terminating in the stigma receptive to pollen), usually located within the ring of anthers in the flower centre, are borne on separate flowers that are located in many separated single sex patches.

       The Mourne Mountains, Co. Down

      The Mourne Mountains stand up as a group of granite hills in south Co. Down with some flanking Silurian rocks. Carlingford Lough lies to the south. Many summits exceed 600 m, and the highest point is Slieve Donard at 850 m. Amongst the granite outcrops are some impressive cliffs and dramatic pinnacles that have originated by longer periods of weathering of the rock. Blanket bog covers the uplands and where the Silurian slates have been worn down by the weather, producing a richer soil, more interesting plants occur. The arctic-alpine and alpine flora is disappointing – already we are on the eastern coast of Ireland – and consists of the usual run-of-the-mill species. Amongst the plants of the higher ground, recorded by Praeger, are alpine saw-wort, dwarf willow, cowberry and alpine clubmoss. Lower altitudes host starry saxifrage, roseroot and the parsley fern. On the high cliffs of Slieve Bignian and Eagle Mountain Praeger recorded the very rare native form of the rosebay willowherb.³ It was still at the latter site in 1985 at an altitude of 455 m.³⁴ Also at the high altitudes are the brittle bladder-fern and the stag’s-horn clubmoss with its long and decorative ‘antlers’.

       The Galty Mountains, Counties Tipperary and Limerick

      The Galtys were thrust up during the dramatic Hercynian earth movements some 300 million years ago that were also responsible for creating the mountain ranges of the southwest of Ireland. This large crustal upfold has been worn down over millions of years. First the uppermost limestones were stripped off the summits, to survive only in the surrounding plains; next, the Old Red Sandstone was eroded along the crest to reveal the old Silurian rocks at the core of the upfold. Thus, the upper parts of the Galtys are made up of Silurian slates, shales and conglomerates to form a series of fine conical peaks that climax at 919 m on Galty Mountain. The bulk of the mountains rise above 762 m. The outstanding arctic plant of the Galtys is the northern rock-cress СКАЧАТЬ